Farnsworth is a snobbish passenger diesel who lives at Kahlville Junction.
The local train between Kahlville and Celgreb City, Farnsworth is easily described as "too big for his wheels", thinking that he should only pull coaches and passenger, and nothing else. He also thinks he shouldn't get up so early, claiming it's bad for his "chug" and that he's a "refined engine". This attitude, as one would expect, is not well like among other Crotoonians, especially his shedmates in Kahlville. Just don't be around when he's seen Spencer! Or you'll be in for a bumpy ride!
Farnsworth first appeared at Kahlville Junction demanding for Tillie to fetch his coaches and boasts about how he can't wait for silly engines like her. Tillie is insulted by this and tells him he is a disposable engine to which Farnsworth is taken aback. He then starts to insult Casey Jr before leaving for Celgreb City.
There he meets Gordon who he mocks for being a tender engine. Gordon defends himself by stating how Farnsworth was late by five minutes. Farnsworth puts the blame on Tillie, a goat on the line and an overheated radiator. That is when the stationmaster tells him to take some goods from Celgreb Bay Harbour with Gordon.
Later at the docks, Farnsworth impatiently pulls out of the docks early and he and Gordon get into a race. They run neck and neck until they reach Great Wolf Junction where the points were against Gordon, causing the two big engines to crash-land into the river nearby. Later Calley arrives to rescue them as they argue over who's to blame. Calley stops them from arguing abruptly.
Farnsworth then joins the other engines at Kahlville to witness Tillie getting rewarded her own mail trucks.
He is based on a Baldwin Sharknose Locomotive, Baldwin RF-16. Chatsworth also shares this basis.
Farnsworth is painted white with a blue base.